The emergence and development of a three-dimensional (3D) laser measurement technology provides a new technical means for the acquisition of spatial 3D information, and provides necessary survival conditions for the digital development of information. The 3D laser scanning measurement technology overcomes the limitations of traditional measurement technology, and uses a way of non-contact active measurement to directly acquire high-precision 3D data. It can scan any object around the clock and quickly convert real-world information into data that can be processed, greatly reducing costs, saving time and facilitating use. Typical products include Switzerland based Leica, Austria based Rigel, Canada based Optech, and America based FARO, and the like.
However, the three-dimensional data characteristics required by particular researching objects are not exactly the same, that is, special requirements will be proposed in the way in which the three-dimensional data are acquired based on different researching objects. For instance, for traditional land surveys, measuring and mapping, building modeling, mineral surveys, and the like, it will be just enough that a three-dimensional point cloud of a surface of an object is macroscopically obtain and the point cloud is utilized to perform modeling, which is characterized by a wide range and a relatively low precision requirements, allowing measurement at a fixed site, requiring the point cloud to cover the object to be studied, and there is no special requirements for the relationship between single points of the point cloud, and the measurement result thereof is typically an absolute distance from the measurement site. For a specific research such as cultural relic archaeology, pavement disease detection, tunnel measurements, foreign object debris and airport pavement disease detection, chip defect detection and the like, it requires measurement in a high dynamic environment, with an accuracy up to micron level, and a special relationship among the point cloud is required, and the measurement result is typically a relative distance to the measured object itself. Macroscopic 3D point cloud acquisition and modeling have been studied a lot at home and abroad, and a 3D laser radar measurement based on laser measurement technology has matured and been widely used. For example, Austria based RIEGL, America based FARO and China based Haida data cloud have mature products, a basic principle of which is to use a rotating prism to measure a single section and rotate a gimbal to scan the entire field of view to obtain a three-dimensional point cloud of the object. Based on the time-of-flight differential pulse measurement, a measurement accuracy reaches millimeter level, and a measurement speed reaches more than one million points per second. The prism and the gimbal may rotate synchronously during measurement, and a measurement section is a non-strict section (obtained not in the same time and space), that is, a three-dimensional point cloud of a surface of the object composed of discrete points. However, in areas such as road detection, tunnel surveying, track defect detection, and cultural relic archaeology, it is required to measure in a high-dynamic environment, and it is required to obtain a section in a strict sense at one measurement, that is, the points on the section are measured at a same attitude and at a same time. For example, for track profile detection and road rutting detection, it requires that a measurement width is at least 2000 mm or more, the measurement resolution (sampling interval for the points on the same section) reaches at least millimeter level, the distance measurement accuracy reaches at least 0.01 mm, and the measurement frequency is 10 KHz or more, i.e., 200 million points may be measured per second. Conventional 3D laser radar measurement techniques are all unable to meet such requirements of measurement. Therefore, research on three-dimensional measurement sensors based on linear scan has great social and economic value.
Internationally, at the beginning of this century, research on linear-scanning 3D measurement technology has been started, such as RANGER series of SICK company in Germany, but which is subject to sensors, and the measurement frequency and accuracy are relatively low. With the development of a new generation of 3D measuring cameras, a section extraction algorithm is integrated in the camera, and the camera outputs a point cloud in image space of a measurement section, so that the frequency is greatly improved, reaching 20 KHz or more, thereby making 3D measurement in high-dynamic environment possible. Although the three-dimensional camera realizes high-frequency extraction of three-dimensional sections, the three-dimensional camera itself cannot directly meet specific measurement requirements of a certain application in the face of different use environments. The three-dimensional camera needs to cope with an appropriate laser light source, merge attitude information according to the environment, control and acquire data synchronously, and realize high-precision conversion and calibration of object space and image space, and needs especially to process data professionally according to requirements of an application. Therefore, it has great practical significance to take a research on 3D measurement sensors integrating 3D cameras, lasers, attitude sensors and data preprocessing methods, design fast, fully automatic and high precision sensor calibration methods and tools, so as to achieve a sensor of high frequency, high precision and allowing measurement in high-dynamic environments.